Mask inspecting apparatus and mask inspecting method which can inspect mask by using electron beam exposure system without independently mounting another mask inspecting apparatus

ABSTRACT

A mask inspecting method includes (a), (b), (c), and (d). The (a) includes providing an electron beam exposure system used for patterning a wafer with a mask. The (b) includes emitting electrons to the mask from the electron beam exposure system. The (c) includes detecting an electron passing through the mask of the emitted electrons. The (d) includes inspecting the mask for a defect based on a detected result of the (c).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an inspecting apparatus and aninspecting method of inspecting a defect of a mask used in an electronbeam exposure system which carries out a pattern transcription by usingan electron beam.

2. Description of the Related Art

Conventionally, a method of emitting a laser light to a mask, andcomparing a pattern generated through its transmission light or itsreflection light with a reference pattern to detect a defect of the maskhas been well known as a method of inspecting a pattern of a mask usedin an electron beam exposure system.

However, when a defect of a stencil mask or a membrane mask used in arecent electron beam exposure system is inspected, a laser light is nottransmitted through the membrane. Thus, there is no method but the usageof the reflection light. It is easy to use the reflection light of thelaser light to then inspect the defect. However, a film thickness of ascattering heavy metal of the membrane mask is typically thin. Hence, itis below a wave length of the laser light. This may result in a fearthat the detection is impossible.

For this reason, the method of inspecting the defect of the membranemask uses a transmission electron microscope (TEM) which uses anelectron beam to thereby inspect the defect of the membrane mask. Inthis TEM, as shown in a schematic configuration of FIG. 1, an electronbeam EB emitted by an electron gun 51 mounted above a mask M isconverged by an optically emitting system 52 containing electron lens53, 54, to be emitted to the mask M. The electron beam transmittedthrough the mask M is passed through an aperture 55 made of Cu materialto be detected by an electron detector 56. The pattern of the mask M isdetected on the basis of a value of a current detected by the electrondetector 56. The detected pattern of the mask M is compared with areference pattern to thereby inspect the defect of the mask M. Thisusage of the electron beam enables the defect of the stencil mask or themembrane mask to be detected. Such technique is disclosed in, forexample, Japanese Laid Open Patent Application (JP-A-Heisei, 4-361544),although it does not describe the membrane mask or the stencil mask inparticular.

A conventional apparatus for inspecting a defect of a mask isconstituted as an apparatus dedicated to a mask inspection. For thisreason, a factory for manufacturing a semiconductor apparatus requiresan equipment of a mask inspecting apparatus, apart from an apparatus formanufacturing a semiconductor apparatus. It requires a reservation ofspace to install the mask inspecting apparatuses in addition to a spaceto install the apparatus for manufacturing the semiconductor apparatusin the manufacturing factory. Also, this type mask inspecting apparatusrequires the configuration similar to that of the electron beam exposuresystem, as an electron gun or an optically emitting system for emittingan electron beam to a mask. This results in a problem that the maskinspecting apparatus becomes larger and more expensive.

Also, in the conventional inspection of the mask defect, the electrondetector detects the electron beam transmitted through the mask tothereby detect the pattern of the mask. Then, the detected pattern iscompared with the reference pattern. Thus, there may be a fear that atrouble is induced in a reliability of the mask defect inspection. Thatis, the detected pattern is made into signals in which the detectedpattern is converted into binary values at a fine region unit. A binarysignal of a fine detecting region of the detected pattern is comparedwith a binary signal of a region corresponding to the fine detectingregion of the reference pattern. Accordingly, a portion where both thesignals are not in coincidence with each other is judged as the defectof the mask. However, in this case, if an error is induced in areference level when each of the fine regions of the detected pattern isconverted into the binary value, the reliability of the binary valueitself in which each of the fine regions of the detected pattern isconverted into the binary value is dropped, which results in a drop of areliability of the defect inspection.

Japanese Laid Open Patent Application (JP-A-Showa, 63-38149) discloses apattern defect inspector as described below. The pattern defectinspector is provided with a device for scanning on a substrate in whichone or more rectangular patterns are formed, a device for detecting asignal occurring from the substrate through the scanning operation, adevice for treating the detected signal and thereby obtaining a binaryinformation, a device for converting the binary information into aplurality of rectangular pattern information, a device for accumulatingtherein the rectangular pattern information, and a device for comparingthe rectangular pattern information with a standard data correspondingto the rectangular pattern information.

SUMMARY OF THE INVENTION

The present invention is accomplished in view of the above mentionedproblems. Therefore, an object of the present invention is to provide amask inspecting apparatus which can inspect a mask by using an electronbeam exposure system and accordingly cancel out a need for anindependent installation of another mask inspecting apparatus. Anotherobject of the present invention is to provide a mask inspecting methodwhich can improve a reliability in an inspection of a defect of a mask.

In order to achieve an aspect of the present invention, a maskinspecting method, includes: (a) providing an electron beam exposuresystem used for patterning a wafer with a mask; (b) emitting electronsto the mask from the electron beam exposure system; (c) detecting anelectron passing through the mask of the emitted electrons; and (d)inspecting the mask for a defect based on a detected result of the (c).

In this case, the (b) is performed such that the electrons emitted fromthe electron beam exposure system are not emitted to the wafer.

Also in this case, the mask inspecting method, further includes: (e)performing an exposure to the wafer through the mask for patterning byusing the electron beam exposure system when the mask has no defect as aresult of the (d).

Further in this case, in the (b) the electrons are emitted from theelectron beam exposure system in such a manner that the (e) isperformed.

In this case, the mask inspecting method, further includes: (f)providing a reference pattern data indicating a reference pattern of themask; and (g) calculating an area rate implying a ratio of a blackpattern to a white pattern included in a portion data corresponding to ainspecting region of the mask of the reference pattern data, and whereinthe (d) includes inspecting the mask for the defect based on thedetected result of the (c) and the area rate.

Also in this case, the (c) includes detecting a strength of the electronpassing through the mask, and the mask inspecting method, furtherincludes: (h) providing a reference pattern data indicating a referencepattern of the mask; and (i) calculating an area rate implying a ratioof a black pattern to a white pattern included in a portion datacorresponding to a inspecting region of the mask of the referencepattern data, and wherein the (d) includes inspecting the mask for thedefect based on the strength of the electron and the area rate.

Further in this case, the mask inspecting method, further includes: (j)calculating a correction value indicating a relation between thestrength of the electron and the reference pattern, and wherein the (d)includes inspecting the mask for the defect based on the strength of theelectron and the correction value, and the area rate.

In this case, the (c) is performed by an electron detector, and whereinthe electron detector is automatically movable from a position where theelectron detector covers a position of the wafer such that the electronpassing through the mask is not emitted to the position of the wafer toanother position where the electron detector does not cover the positionof the wafer such that the electron passing through the mask is emittedto the position of the wafer.

Also in this case, the (c) includes detecting the electron passingthrough the mask to detect a position in the electron detector when theelectron is inputted to the electron detector and a strength of theinputted electron.

Further in this case, the electron detector includes a plurality ofdiodes arranged in a form of array.

In this case, the electron detector includes a plurality of diodesarranged in a grid form.

Also in this case, the mask inspecting method, further includes: (k)providing an MCP (Micro Channel Plate) having a plurality of holes in aposition between the electron detector and the mask; and (1) applying avoltage to the MCP, and wherein the (c) includes detecting a position inthe MCP when the electron is inputted to the MCP and a strength of theinputted electron.

In order to achieve another aspect of the present invention, a maskinspecting apparatus, includes: an electron beam exposure system usedfor patterning a wafer with a mask, the electron beam exposure systememitting electrons to the mask; an electron detector detecting anelectron passing through the mask of the emitted electrons; and aninspecting unit inspecting the mask for a defect based on a detectedresult by the electron detector.

In this case, when the electron detector detects the electron passingthrough the mask, the electrons emitted from the electron beam exposuresystem are not emitted to the wafer.

Also in this case, the electron beam exposure system performs anexposure to the wafer through the mask for patterning when the mask hasno defect as an inspection result by the inspecting unit.

Further in this case, when the electron detector detects the electronpassing through the mask, the electron beam exposure system emits theelectrons in such a manner that the electron beam exposure systemperforms the exposure to the wafer through the mask for patterning.

In this case, the inspecting unit stores a reference pattern dataindicating a reference pattern of the mask and calculates an area rateimplying a ratio of a black pattern to a white pattern included in aportion data corresponding to a inspecting region of the mask of thereference pattern data, and wherein the inspecting unit inspects themask for the defect based on the detected result by the electrondetector and the area rate.

Also in this case, the electron detector detects a strength of theelectron passing through the mask, and wherein the inspecting unitstores a reference pattern data indicating a reference pattern of themask and calculates an area rate implying a ratio of a black pattern toa white pattern included in a portion data corresponding to a inspectingregion of the mask of the reference pattern data, and wherein theinspecting unit inspects the mask for the defect based on the strengthof the electron and the area rate.

Further in this case, the inspecting unit calculates a correction valueindicating a relation between the strength of the electron and thereference pattern, and wherein the inspecting unit inspects the mask forthe defect based on the strength of the electron and the correctionvalue, and the area rate.

In this case, the electron detector is automatically movable from aposition where the electron detector covers a position of the wafer suchthat the electron passing through the mask is not emitted to theposition of the wafer to another position where the electron detectordoes not cover the position of the wafer such that the electron passingthrough the mask is emitted to the position of the wafer.

Also in this case, the electron detector detects the electron passingthrough the mask to detect a position in the electron detector when theelectron is inputted to the electron detector and a strength of theinputted electron.

Further in this case, the electron detector includes a plurality ofdiodes arranged in a form of array.

In this case, the electron detector includes a plurality of diodesarranged in a grid form.

Also in this case, the mask inspecting apparatus, further includes:

an MCP (Micro Channel Plate) having a plurality of holes in a positionbetween the electron detector and the mask, a voltage being applied tothe MCP, and wherein the MCP detects a position in the MCP when theelectron is inputted to the MCP and a strength of the inputted electron.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing a diagrammatic configuration of aconventional mask inspecting apparatus;

FIG. 2 is a front view showing a diagrammatic configuration of a maskinspecting apparatus of an embodiment of the present invention;

FIG. 3 is a diagrammatically perspective configuration view of the maskinspecting apparatus of FIG. 2;

FIG. 4A is a perspective view showing a configuration of an electrondetector contained in the mask inspecting apparatus of FIG. 2;

FIG. 4B is a section view showing a configuration of the electrondetector contained in the mask inspecting apparatus of FIG. 2;

FIG. 5 is a concept view describing a current detection operation ateach diode of the electron detector contained in the mask inspectingapparatus of FIG. 2;

FIG. 6 is a flowchart showing an algorithm in a mask inspecting methodof an embodiment of the present invention;

FIG. 7A is a perspective view showing another example of the electrondetector contained in the mask inspecting apparatus of FIG. 2; and

FIG. 7B is a perspective view showing MCP used in the mask inspectingapparatus of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below withreference to the drawings.

FIG. 2 is a side view showing a mask inspecting apparatus in thisembodiment. FIG. 3 is a perspective view showing the mask inspectingapparatus in this embodiment. A mask inspecting apparatus 2 in thisembodiment is constituted by an electron beam exposure system 1 fordrawing a picture through scattering electrons.

The mask inspecting apparatus 2 inspects a defect of a scattering maskM. The scattering mask M has a pattern needed for a transcription to awafer W.

The mask inspecting apparatus 2 is provided with an electron gun 11 foremitting an electron beam, electron lens 13, 14, a blanking aperture 15,electron lens 17, 18 and a backward focal plane aperture 19.

The electron lens 13, 14 and the blanking aperture 15 are contained inan optically emitting system 12. The electron lens 17, 18 and thebackward focal plane aperture 19 are contained in an optically imagingsystem 16.

The electron lens 13, 14 converge electron beams EB emitted by theelectron gun 11. The blanking aperture 15 converts a flux of electronbeams into a necessary shape. The electron lens 17, 18 are used toproject and transcript the electron beams EB scattering by thescattering mask M to the wafer W.

An electron detector 20 for inspecting the mask defect is mountedimmediately beneath the scattering mask M. When the pattern istranscribed to the wafer W, the electron detector 20 is detached fromthe electron beam exposure system 1 such that a usual operation forexposing an electron beam EB can be performed. On the other hand, theelectron detector 20 is mounted within the electron beam exposure system1 at a time of the inspection of the defect of the mask M.

By the way, a loading mechanism 21 is mounted such that the electrondetector 20 can be mounted in and detached from the electron beamexposure system 1. However, the detailed explanation thereof is omittedhere. Moreover, a computer 30 is connected to the electron beam exposuresystem 1 (mask inspecting apparatus 2) so that the defect of the mask Mis inspected.

Here, the already-known membrane mask or stencil mask is used as thescattering mask M. In the membrane mask, a pattern, which services as ascatterer and has a high atomic number and a high density, is formed ona membrane film made of a material having a low atomic number and a lowdensity. A difference between scattering degrees of electrons is used toreserve a beam contrast. The stencil mask slightly differs from themembrane mask in that a pattern portion of the stencil mask is made of amaterial having a thick film, such as silicon or the like. However, thestencil mask basically has the configuration similar to that of themembrane mask.

The mask M can be moved in a direction of a flat surface XY through amask stage (not shown). So, the entire pattern of the mask M istranscribed to the wafer W while moved in the direction of the flatsurface XY. The wafer W is similarly placed on a wafer stage (notshown), and can be moved in the direction of the flat surface XY,synchronously with the mask stage.

As shown in FIG. 4A, the electron detector is configured such thatdiodes 210, 220 arranged in upper and lower two layers, respectively,and made of thin film silicon are arranged in a form of array. As shownin FIG. 4B, in the diodes 210 of the lower layer and the diodes 220 ofthe upper layer, a plurality of N-type impurity layers 212, 222 whichare rectangular-shaped and extending in an X-direction and aY-direction, respectively, are arranged parallel to each other onsurface portions of P-type thin film silicon 211, 221, respectively.Also, in the diodes 210 of the lower layer and the diodes 220 of theupper layer, amplifiers 213, 223 respectively composed of transistorsand the like are formed at both ends in longitudinal directions of therespective N-type impurity layers 212, 222, respectively.

A reverse bias is applied between the P-type thin film silicon 211, 221and the N-type impurity layers 212, 222 so that a steady state is keptin which currents do not flow. Then, currents caused by holes and secondelectrons generated by electrons inputted to the N-type impurity layers212, 222 of the respective diodes 221, 220 are amplified by therespective amplifiers 213, 223 to thereby detect the values of thecurrents. Also, the computer 30 uses those current values to detect thepositions of the input electrons, and thereby inspect the mask defect.

That is, in FIG. 3, the computer 30 is provided with a memory 32, suchas a record disc or the like, a position controller 31, an area ratecalculator 33 and a defect judge section 34.

The position controller 31 controls a movement position in the XYdirections on the flat surface of the mask stage (not shown) in whichthe mask M is at least placed.

The area rate calculator 33 reads out a pattern data corresponding to apattern of an open region of the mask M limited by the blanking aperture15, namely, an inspection region, from the memory 32, in accordance withan information of an XY position controlled by the position controller31. Then, it calculates an area rate of the pattern data, namely, “arearate” implying a ratio of a black pattern to a white pattern in themask. The calculated area rate is reference data when the defect judgesection 34 performs a defect judgement.

The defect judge section 34 compares the calculated area rate with acurrent value which is a measured result of a current amplified by eachof the amplifiers 213, 223 of the electron detector 20. Accordingly, itjudges a white defect (an omission of a pattern region) and a blackdefect (an excessive pattern) in the mask, in accordance with thecompared result.

The mask inspecting apparatus 2 using the electron beam exposure system1 having the above-mentioned configuration will be described below.

At first, before the mask is usually transcribed, the electron detector20 is mounted in a portion immediately beneath the mask M within theelectron beam exposure system 1, as shown in FIGS. 2 and 3.

Next, similarly to the case of the pattern transcription, the opticallyemitting system 12 emits the electron beam emitted by the electron gun11 to the mask M set in the electron beam exposure system 1. Here, asmentioned above, the pattern portion on the membrane mask is made of theheavy metal, and the pattern portion of the stencil mask is made of thematerial having the thick film such as silicon and the like. So, theelectrons emitted to the pattern portion of the membrane mask or thestencil mask are scattering at a large angle a plurality of times. Thus,there is a high possibility that the electrons emitted to the patternportion are scattering outside the electron detector 20. Or, even ifelectrons emitted to the pattern portion are tentatively inputted to theelectron detector 20, the number of electrons scattering at the sameangle as the inputted electrons is relatively small. Hence, the signalbecomes very weal so that it can not be detected. Electrons emitted to aportion having no pattern, namely a portion other than the patternportion are transmitted through the mask M to be inputted to therespective diodes 210, 220 of the electron detector 20. The electronbeams inputted to the respective diodes 210, 220 excite silicon atoms inthe material the respective diodes 210, 220 of at a certain probabilityto generate the second electrons and the holes.

Those second electrons and those holes are moved to the amplifiers 213by an electric field applied to the diode 210 (the P-type silicon 211and the N-type impurity layers 212), as shown in the concept view of thediode 210 of FIG. 5. At this time, since the silicon diode 210 has acertain resistance, the resistance causes the current to be attenuatedat a certain rate. The inputted position of the electron can bespecified by measuring the rate of the attenuation based on the currentread out from the amplifiers 213 on both the sides of the diodes 210.Moreover, a strength of the electron can be specified based on thecurrent value. By the way, the specified inputted position is a positionin the X-direction in the case of the lower layer diodes 210, and aposition in the Y-direction in the case of the upper layer diodes 220.Thus, the total consideration with regard to such positions enables theposition on the flat surface XY of the electron detector 20 to bespecified.

The position and the strength of the electron specified as mentionedabove are inputted to the computer 30, which judges the defect of themask.

FIG. 6 is a flowchart showing an algorithm to judge the mask defect. Atfirst, the computer 30 controls the mask stage so that an inspectionregion targeted for the inspection of the mask M is positionedcorrespondingly to the aperture 15 of the optically emitting system 12(S101). Accordingly, an electron beam, which is emitted by the electrongun 11 and then transmitted through an opening of the blanking aperture15 is emitted to the inspection region of the pattern of the mask M(S102). Thus, the electron beam transmitted through the mask M isinputted to the electron detector 20. As mentioned above, the inputtedposition of the electron beam is specified in accordance with thecurrent outputted by the amplifiers of the electron detector 20. Alsothe strength of the electron beam is specified based on the measuredcurrent value.

On the other hand, the computer 30 reads out a pattern data of the maskM from the memory 32 which stores therein the information of the patterndata of the mask M as the inspection target (S104). Then, a regionhaving the same area as the opening of the blanking aperture 15 isdivided into a mesh to be set, based on an XY position of the inspectionregion of the mask M (S105). After that, the area rate calculator 33calculates an area rate of the mask based on the pattern data of the setregion (S106). This area rate implies a rate of a black pattern to awhite pattern in the mask region, as mentioned above.

Next, the defect judge section 34 correlates the inputted position ofthe electron beam detected at the step S103 with the region of the maskM set at the step S105, and then compares the area rate calculated atthe step S106 with the current value measured at the step S103 (S107) tojudge the white defect and the black defect in the mask M, in accordancewith the compared result (S108).

By the way, in this comparison, only the numerals except the units ofthe respective values are compared (S107). So, a case of [AreaRate=Current Value] is judged as a no-defect, a case of [AreaRate>Current Value] is judged as the black defect, and a case of [AreaRate<Current Value] is judged as the white defect (S108).

The judgment is repeatedly performed on all regions targeted for themask inspection, and then the mask inspection is completed (S109, S110).

Here, in the comparison between the area rate and the current value, itis desirable to use the mask, in which a fact that the mask does nothave any defect is known in advance and then calculate a correctionvalue indicating a relation between the electron strength and a presenceor an absence of the pattern.

This correction value is added to, for example, the current value. Then,the value in which the correction value is added to the current value iscompared with the area rate, similarly to the above-mentioned case.Thus, it is possible to cancel out an influence of a detection error inthe current value to thereby improve a judgment accuracy of the defect.

The inspection of the defect in the mask can be attained in this way.So, if the electron detector 20 is mounted inside the electron beamexposure system 1, the electron beam exposure system 1 can be configuredin its original state as the mask inspecting apparatus 2. Thus, thefactory for manufacturing the semiconductor apparatus does not need toconfigure the mask inspecting apparatus as the independent apparatus.Hence, this is advantageous in reducing a facility space and reducing anentire cost of an equipment for manufacturing the semiconductorapparatus.

The mask M set in the electron beam exposure system 1 can be used in itsoriginal state for the exposure to the wafer W after the completion ofthe mask inspection. Thus, it is also possible to reduce a loss of aprocessing time caused by the movement between the apparatuses of themask M.

Moreover, at the time of the inspection of the mask M, the area ratedetermined based on the pattern data of the mask M is compared with thecurrent value obtained by the electron detector 20. Thus, it is possibleto protect the drop of the reliability caused by the error of thereference level when the data is converted into the binary value.

Moreover, instead of the reflection electron or the reflection light inwhich only the influence on the surface can be considered, thetransmission electron is used in which the rate of energy attenuation isdifferent depending on the film thickness. Thus, it is possible toconsider the influence of the values (the film thickness of the mask Mand the like) contributing to the electron scattering whose appearancecan not be inspected.

A grid type of an electron detector 20A in which diodes made of siliconare arranged in XY directions, respectively, as shown in FIG. 7A can beused as a variation of the electron detector 20 used in the embodiment.In this case, an information as to which diode is irradiated withelectrons of what strength can be detected based on the current detectedin the X-direction and the current detected in the Y-direction. Hence, atwo-dimension position and current position can be detected based on thedetected information.

Also, as shown in FIG. 7B, an MCP (Micro Channel Plate) 40 of a siliconplate having many holes to which a voltage is applied is mounted betweena position immediately beneath the mask M and the electron detector 20or 20A. The MCP 40 is used as a position detector. Also in this case, itis possible to detect an information with regard to the hole to which anelectron is inputted and a strength of the inputted electron.

As mentioned above, in the mask inspecting apparatus according to thepresent invention, the electron detector for detecting the electron beamtransmitted through the mask for the mask inspection can be mountedinside and detached from the portion immediately beneath the mask withinthe electron beam exposure system in which the mask is set. Thus, if theelectron detector is mounted within the electron beam exposure system,the electron beam exposure system can be configured in its originalstate as the mask inspecting apparatus.

Thus, it is not necessary to configure the mask inspecting apparatusindependently of the electron beam exposure system. So, this isadvantageous in reducing the facility space in the factory formanufacturing the semiconductor apparatus and the like, and reducing theentire cost of the equipment for manufacturing the semiconductorapparatus. Also, the mask set in the electron beam exposure system canbe used in its original state for the exposure to the wafer after thecompletion of the mask inspection. Hence, it is also possible to reducethe loss of the processing time caused by the movement between theapparatuses of the mask.

Moreover, the mask inspecting method in the present invention comparesthe area rate determined based on the pattern data of the mask targetedfor the inspection with the current value obtained by the electrondetector for detecting the electron beam transmitted through the mask.Thus, it is possible to protect the drop of the reliability caused bythe error of the reference level when the data is converted into thebinary value. Furthermore, the defect of the mask can be inspected atthe high accuracy and at the high reliability.

What is claimed is:
 1. A mask inspecting method, comprising: (a)providing an electron beam exposure system used for patterning a waferwith a mask; (b) emitting electrons to said mask from said electron beamexposure system; (c) detecting an electron passing through said mask ofsaid emitted electrons; and (d) inspecting said mask for a defect basedon a detected result of said (c).
 2. The mask inspecting methodaccording to claim 1, wherein said (b) is performed such that saidelectrons emitted from said electron beam exposure system are notemitted to said wafer.
 3. The mask inspecting method according to claim1, further comprising: (e) performing an exposure to said wafer throughsaid mask for patterning by using said electron beam exposure systemwhen said mask has no defect as a result of said (d).
 4. The maskinspecting method according to claim 3, wherein in said (b) saidelectrons are emitted from said electron beam exposure system in such amanner that said (e) is performed.
 5. The mask inspecting methodaccording to claim 1, further comprising: (f) providing a referencepattern data indicating a reference pattern of said mask; and (g)calculating an area rate implying a ratio of a black pattern to a whitepattern included in a portion data corresponding to a inspecting regionof said mask of said reference pattern data, and wherein said (d)includes inspecting said mask for said defect based on said detectedresult of said (c) and said area rate.
 6. The mask inspecting methodaccording to claim 1, wherein said (c) includes detecting a strength ofsaid electron passing through said mask, and said mask inspectingmethod, further comprising: (h) providing a reference pattern dataindicating a reference pattern of said mask; and (i) calculating an arearate implying a ratio of a black pattern to a white pattern included ina portion data corresponding to a inspecting region of said mask of saidreference pattern data, and wherein said (d) includes inspecting saidmask for said defect based on said strength of said electron and saidarea rate.
 7. The mask inspecting method according to claim 6, furthercomprising: (j) calculating a correction value indicating a relationbetween said strength of said electron and said reference pattern, andwherein said (d) includes inspecting said mask for said defect based onsaid strength of said electron and said correction value, and said arearate.
 8. The mask inspecting method according to claim 1, wherein said(c) is performed by an electron detector, and wherein said electrondetector is automatically movable from a position where said electrondetector covers a position of said wafer such that said electron passingthrough said mask is not emitted to said position of said wafer toanother position where said electron detector does not cover saidposition of said wafer such that said electron passing through said maskis emitted to said position of said wafer.
 9. The mask inspecting methodaccording to claim 8, wherein said (c) includes detecting said electronpassing through said mask to detect a position in said electron detectorwhen said electron is inputted to said electron detector and a strengthof said inputted electron.
 10. The mask inspecting method according toclaim 8, wherein said electron detector includes a plurality of diodesarranged in a form of array.
 11. The mask inspecting method according toclaim 8, wherein said electron detector includes a plurality of diodesarranged in a grid form.
 12. The mask inspecting method according toclaim 8, further comprising: (k) providing an MCP (Micro Channel Plate)having a plurality of holes in a position between said electron detectorand said mask; and (l) applying a voltage to said MCP, and wherein said(c) includes detecting a position in said MCP when said electron isinputted to said MCP and a strength of said inputted electron.
 13. Amask inspecting apparatus, comprising: an electron beam exposure systemused for patterning a wafer with a mask, said electron beam exposuresystem emitting electrons to said mask; an electron detector detectingan electron passing through said mask of said emitted electrons; and aninspecting unit inspecting said mask for a defect based on a detectedresult by said electron detector.
 14. The mask inspecting apparatusaccording to claim 13, wherein when said electron detector detects saidelectron passing through said mask, said electrons emitted from saidelectron beam exposure system are not emitted to said wafer.
 15. Themask inspecting apparatus according to claim 13, wherein said electronbeam exposure system performs an exposure to said wafer through saidmask for patterning when said mask has no defect as an inspection resultby said inspecting unit.
 16. The mask inspecting apparatus according toclaim 15, wherein when said electron detector detects said electronpassing through said mask, said electron beam exposure system emits saidelectrons in such a manner that said electron beam exposure systemperforms said exposure to said wafer through said mask for patterning.17. The mask inspecting apparatus according to claim 13, wherein saidinspecting unit stores a reference pattern data indicating a referencepattern of said mask and calculates an area rate implying a ratio of ablack pattern to a white pattern included in a portion datacorresponding to a inspecting region of said mask of said referencepattern data, and wherein said inspecting unit inspects said mask forsaid defect based on said detected result by said electron detector andsaid area rate.
 18. The mask inspecting apparatus according to claim 13,wherein said electron detector detects a strength of said electronpassing through said mask, and wherein said inspecting unit stores areference pattern data indicating a reference pattern of said mask andcalculates an area rate implying a ratio of a black pattern to a whitepattern included in a portion data corresponding to a inspecting regionof said mask of said reference pattern data, and wherein said inspectingunit inspects said mask for said defect based on said strength of saidelectron and said area rate.
 19. The mask inspecting apparatus accordingto claim 18, wherein said inspecting unit calculates a correction valueindicating a relation between said strength of said electron and saidreference pattern, and wherein said inspecting unit inspects said maskfor said defect based on said strength of said electron and saidcorrection value, and said area rate.
 20. The mask inspecting apparatusaccording to claim 13, wherein said electron detector is automaticallymovable from a position where said electron detector covers a positionof said wafer such that said electron passing through said mask is notemitted to said position of said wafer to another position where saidelectron detector does not cover said position of said wafer such thatsaid electron passing through said mask is emitted to said position ofsaid wafer.
 21. The mask inspecting apparatus according to claim 13,wherein said electron detector detects said electron passing throughsaid mask to detect a position in said electron detector when saidelectron is inputted to said electron detector and a strength of saidinputted electron.
 22. The mask inspecting apparatus according to claim13, wherein said electron detector includes a plurality of diodesarranged in a form of array.
 23. The mask inspecting apparatus accordingto claim 13, wherein said electron detector includes a plurality ofdiodes arranged in a grid form.
 24. The mask inspecting apparatusaccording to claim 13, further comprising: an MCP (Micro Channel Plate)having a plurality of holes in a position between said electron detectorand said mask, a voltage being applied to said MCP, and wherein said MCPdetects a position in said MCP when said electron is inputted to saidMCP and a strength of said inputted electron.